/*
 * YAJHFC - Yet another Java Hylafax client
 * Copyright (C) 2005-2013 Jonas Wolz <info@yajhfc.de>
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *  Linking YajHFC statically or dynamically with other modules is making 
 *  a combined work based on YajHFC. Thus, the terms and conditions of 
 *  the GNU General Public License cover the whole combination.
 *  In addition, as a special exception, the copyright holders of YajHFC 
 *  give you permission to combine YajHFC with modules that are loaded using
 *  the YajHFC plugin interface as long as such plugins do not attempt to
 *  change the application's name (for example they may not change the main window title bar 
 *  and may not replace or change the About dialog).
 *  You may copy and distribute such a system following the terms of the
 *  GNU GPL for YajHFC and the licenses of the other code concerned,
 *  provided that you include the source code of that other code when 
 *  and as the GNU GPL requires distribution of source code.
 *  
 *  Note that people who make modified versions of YajHFC are not obligated to grant 
 *  this special exception for their modified versions; it is their choice whether to do so.
 *  The GNU General Public License gives permission to release a modified 
 *  version without this exception; this exception also makes it possible 
 *  to release a modified version which carries forward this exception.
 */
package yajhfc.file;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.LinkedList;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * @author jonas
 *
 */
public class StdErrThread extends Thread {
    private static final Logger log = Logger.getLogger(StdErrThread.class.getName());
    
	protected final String commandName;
	protected final InputStream errStream;
	protected final LinkedList<String> tail = new LinkedList<String>();
	protected final int maxTail;
	
	public StdErrThread(String commandName, InputStream errStream) {
		this(commandName, errStream, 10);
	}
	
	public StdErrThread(String commandName, InputStream errStream, int maxTail) {
		super("StdErrThread-" + commandName );
		this.commandName = commandName;
		this.errStream = errStream;
		this.maxTail = maxTail;
		setDaemon(true);
		setPriority(MIN_PRIORITY);
		start();
	}
	
	@Override
	public void run() {
        try {
			BufferedReader errReader = new BufferedReader(new InputStreamReader(errStream));
			String line;
			while ((line = errReader.readLine()) != null) {
			    log.info(commandName + " output: " + line);
			    tail.offer(line);
			    while (tail.size() > maxTail) {
			        tail.poll();
			    }
			}
			errReader.close();
		} catch (Exception e) {
			log.log(Level.WARNING, "Error reading stderr for " + commandName, e);
		}
	}
	
	public LinkedList<String> getTail() {
		return tail;
	}
}
